DASH Diet's Potassium Load Found Safe Alongside Blood Pressure Drugs, Study Suggests

A potassium-rich diet long recommended for lowering blood pressure does not appear to push blood potassium to dangerous levels in people who are also taking common blood pressure drugs, according to findings presented Thursday at the American Heart Association's Hypertension Scientific Sessions 2026 in Arlington, Virginia. The question has hung over the DASH diet for years: medications such as ACE inhibitors, ARBs and potassium-sparing diuretics already raise potassium on their own, and doctors have had little trial evidence on whether adding a potassium-heavy eating pattern on top of those drugs is safe.

The new analysis, a secondary look at two randomized trials run out of Beth Israel Deaconess Medical Center in Boston, found no meaningful rise in blood potassium among participants on any of five medication classes after twelve weeks on a DASH-patterned diet. The work has not yet been published in a peer-reviewed journal; it was presented as a conference poster, and the authors describe it as preliminary.

What the data show

Researchers drew on 356 Black adults in the greater Boston area, average age 53 and about 70 percent women, who had systolic blood pressure between 120 and just under 150 mm Hg. Some were taking blood pressure medications; others were not. Half the group received twelve weeks of weekly, home-delivered groceries patterned on the DASH diet, along with weekly nutrition counseling. The other half received a cash stipend every four weeks to shop for themselves, with no counseling. The DASH groceries were built to deliver roughly 4,700 milligrams of potassium a day, with a potassium-to-sodium ratio of about two to one.

Average serum potassium at the start of the study was 4.16 millimoles per liter in the grocery-delivery group and 4.18 in the stipend group, both within the normal range. After twelve weeks, neither group showed a statistically significant increase, and within the DASH group, potassium levels did not differ depending on which of the five medication classes a participant was taking: ACE inhibitors, angiotensin receptor blockers, potassium-sparing diuretics, beta blockers or NSAIDs. Kidney function also did not change significantly in either arm, according to the researchers, though the reporting on the presentation notes that exact kidney-function figures were not released alongside the topline results.

How the question arose

The analysis builds on two related trials, known as GoFresh and GoFreshRx, both run through Beth Israel Deaconess Medical Center and registered on the federal clinical trials registry. The original GoFreshRx results, in 176 Black adults with medically treated hypertension, were presented at the American College of Cardiology's 2026 meeting and published simultaneously in Nature Medicine in March. That trial found that participants receiving weekly DASH-patterned grocery deliveries saw their systolic blood pressure fall by about 7 mm Hg over twelve weeks, compared with a 2 mm Hg drop among those given a cash stipend to shop on their own, along with a modest additional reduction in LDL cholesterol. Those blood-pressure gains were the headline result. What they left unanswered was whether a diet deliberately engineered to be high in potassium was safe for people already on medications that can themselves elevate potassium, a combination that can, in rare cases, disrupt heart rhythm. The new secondary analysis, presented this week, was designed to answer that narrower safety question using the same participant pool.

Who the findings affect

The trials recruited specifically from Boston neighborhoods with limited grocery access, sometimes called food deserts, a population the researchers say faces higher rates of diet-related cardiovascular disease and more barriers to following dietary advice from a doctor. Participants were recruited through word of mouth, mailers, and social media and transit advertising. The study excluded people with stage 4 or 5 chronic kidney disease and those who already had elevated potassium at baseline, two groups for whom the standard medical caution about potassium-rich diets still applies. More broadly, the finding is most relevant to the large number of American adults who have high blood pressure and take one or more of the medication classes studied, and whose clinicians have sometimes hesitated to recommend a DASH-style diet out of concern over potassium buildup.

"Managing and monitoring potassium levels is key because they have a direct impact on heart function," said Kevin Volpp, M.D., Ph.D., of the University of Pennsylvania, an American Heart Association volunteer expert who was not involved in the study, adding that the follow-up analysis was an important one because it confirmed that significant potassium increases did not occur with the DASH diet.

Reaction from researchers

Marian Budu, the study's presenting author and a clinical research coordinator on the GoFresh trials at Beth Israel Deaconess, said the results offer reassurance that a well-established dietary pattern can be recommended more broadly. "The DASH diet is a well-known, proven nutrition pattern that is known to improve blood pressure," Budu said, according to the medical center's own account of the broader research program, and the new data suggest it can be prescribed to a wider range of patients without a separate potassium workaround. Volpp, who leads the American Heart Association's Health Care by Food initiative, cautioned that the finding does not resolve every open question, since it does not address whether the diet would be safe for patients who already have somewhat elevated potassium levels or more significantly impaired kidney function, groups the trial excluded by design.

Both researchers and the Heart Association's own materials describe the result as encouraging rather than conclusive. Conference abstracts are not peer-reviewed, and the full data are not scheduled to appear in the journal Hypertension until mid-November. The study is also narrow in its own right: all participants were Black adults living in a single metropolitan area, which the authors acknowledge may limit how far the findings can be generalized to other populations.

What happens next

The researchers say future studies should specifically examine people with borderline-high potassium or reduced kidney function, the two groups current guidance already treats with caution and whom this analysis did not include. The American Heart Association, which funded the research, has said it intends to help scale the broader GoFresh grocery-delivery model to other cities, including sites in Florida, Georgia and Tennessee, building on the blood-pressure results published earlier this year. For now, the immediate clinical message from this week's presentation is narrower: in a closely monitored trial population, adding a potassium-rich diet on top of common blood pressure medications did not push potassium into dangerous territory, a result that researchers say should factor into how freely clinicians recommend the DASH diet to patients who are also on drug therapy for hypertension.